Sotheby's will be selling off a portion of Polaroid's collection next week.
Most notable are Ansel Adam's Moonrise, Hernandez, New Mexico. The image was featured in his book on Polaroid Land Photography - an addendum, sort of - of his The Camera, The Negative, and The Print series of instructional photo books.
The above image is Adams'Tetons and Snake River.
Also in the collection will be some from Robert Mappelthorpe. I'd be very interested to see which images of his will be up for sale.